A standard apparatus for erecting box parts normally has a frame on which is carried a bin for holding a stack of the box blanks, an extractor for picking the blanks one at a time out of the bin, and a conveyor for delivering the blanks to an erecting unit which folds the blanks one at a time into the desired three-dimensional shape. Such a device works automatically and at high speed to produce a succession of set-up box parts, that is normally either bases or lids.
The extractor normally slides or pivots between a position engaging the top or bottom blank in the stack and a position setting the blank on the conveyor. The conveyor in turn has stops that catch on the blank deposited on it so that it is positively entrained.
Such a device is fairly complex mainly as a result of the path the blanks must follow on moving from the stack to the erecting unit. As a result it is fairly difficult to switch from a blank of one size and shape to one of a different size and shape, as such changeover entails reworking the movement of the extractor as well as the stops on the conveyor belt.